Combination driving point and compression connector for ground rod and ground conductor



Oct. 23, 1962 J. SPURGEON 3,069,257

COMBINATION v POINT AND COMPRESSION CONNECTOR FOR UND ROD AND GROUND CONDUCTOR Filed Feb. 2, 1961 2 Sheets-Sheet 1 INVEN TOR. SAMUEL J 6PUIFGOIY O 1962 s. J. SPURGEON COMBINATION DRIVING NT A c PRESSION CONNECTO FOR GROUND R AND CONDUCTOR 2 Sheets-Sheet 2 Filed Feb. 2, 1961 Tia. E.

Ti, .eJ.

l INVENTOR.

Sam/6L J. 5/ 1/ 660 United States Patent 3,060,257 COMBINATION DRIVING POINT AND COMPRES- SION CONNECTOR FOR GROUND ROD AND GROUND CONDUCTOR Samuel J. Spurgeon, Birmingham, Ala., assignor to Anderson Electric Corporation, Birmingham, Ala., a corporation of Alabama Filed Feb. 2, 1961, Ser. No. 86,725 13 Claims. (Cl. 174-7) This invention relates to electrical grounding apparatus, and more particularly, to a driving point for facilitating penetration of the earth by a ground rod and at the same time interconnecting an electrical ground conductor with the ground rod by compression.

One of numerous methods of electrical earth grounding is to drive a metallic member into the earth to suificient depth to contact an earth stratum that has good electrical conductivity characteristics. To this member is attached the grounding conductor of the electrical circuit. In many cases a stratum which provides a sufficiently good electrical conductivity is obtained only at depths exceeding the usual six feet to ten feet length ground rods. The usual method of reaching greater depths with ground rods is to drive sectional rods with screwed connections between sections. These are sometimes driven to depths exceeding fifty feet. The cost of such ground installations are relatively high yet only the small section of the ground rod which contacts the grounding stratum is eifective as a grounding electrode.

It is an object of the present invention to provide a grounding apparatus of the above type having unique and novel characteristics including a driving rod section which is recoverable leaving the ground or electrode section at its desired depth.

Another object is to provide a combination driving point and compressor head which quickly and firmly affixes the ground wire to the ground rod without complicated manipulation of parts or tools.

Briefly the present invention comprises a driving point having a tapered or pointed head which has a generally elliptical cross-section and a central cylindrical bore extending axially into the head. The bore has a flat bottom seat portion. A peripheral grooved portion of the head extends axially along opposedsides of the bore with a curved intermediate bottom portion extending through said seat. The opposed upper ends of the grooved portion are aligned with the major axis of the elliptical crosssection and the depth of the grooved portion gradually decreases to minimum values at the intersections thereof with the plane of the seat.

The lower terminal end portion of the ground conductor is looped and disposed in the grooved portion of the head, and the lower end portion of the ground rod or electrode section is disposed in said bore against the ground conductor in compressing relation therewith along said opposed sides, and in crimping relation therewith at said intersections.

Lateral spacer means may be provided on the ground rod section and is interconnected with the ground conductor for maintaining said conductor radially spaced from said ground rod section.

Axially removable slip-fit coupling means releasably joins the bottom rod section and the driving rod section, and the individual sections comprising the driving rod section are interconnected with one another for axial removal as a group from said bottom rod section.

in another embodiment of the invention the driving point has a peripheral grooved portion of different diameters on the opposed sides of the central cylindrical bore in order to accommodate simultaneously two separate ground wires or conductors of difierent diameters. The conductor Patented Oct. 23., 1962 "ice ends are bent at substantially right angles to their lengths and inserted in their respective grooved portions and then the driving point is hammered onto the ground rod or electrode section in the usual fashion. When using the driving point with only the smaller diameter conductor it can be looped around the grooved portion of the head as in the first embodiment described above.

Other objects and features of the invention will become apparent from the following description and claims and in the drawings, in which:

FIG. 1 is an elevation showing the overall grounding apparatus combination;

FIG. 2 is an enlarged perspective view of the driving point;

FIG. 3 is an enlarged elevation of the head and associated components in partial section;

FIG. 4 is a view similar to that of FIG. 3 including a fragmentary view of the ground rod and conductor;

FIG. 5 is a view taken along lines 5-5 of FIG. 4;

FIG. 6 is a perspective view of a second embodiment of the invention having opposed groove portions of difierent diameters;

FIG. 7 is a partially sectioned elevation of the device shown in FIG. 6; and

FIG. 8 is a section taken along lines 88 of FIG. 7.

Referring now to the drawings, and in particular, FIGS. 2, 3 and 5, the combination driving point and compressor head of the present invention is indicated generally by the reference numeral 10. The driving point or head is a metallic casting of bronze or any other suitable material and has a body portion 11 having a pointed lower closed end 12 and an open upper end 13. The head has a generally elliptical or elongated cross-section (see FIG. 5) and has a centrally disposed cylindrical bore 14 extending axially into the head providing a socket which extends inwardly from the upper end of the head. The bore 14 has a fiat bottom seat portion 15.

Peripheral grooved portion 16 extends axially into head 10 along opposed sides 17, 18 of cylindrical bore 14 and has a curved intermediate bottom portion 19 extending through seat 15 (see FIG. 3). That is, 17 and 18 constitute axial grooves at opposite sides of the socket or bore 14, and 19 is a transverse groove at the bottom of this socket. Groove 19 is narrower than the socket and projects laterally on opposite sides of the socket to join grooves 17 and 18 at points 22 and 23 respectively.

The opposed upper ends 20, 21 of grooved portion 16 are aligned with the major axis of the elliptical crosssection of head 10 and the depth of the grooved portion 16 tapers or gradually diminishes or decreases to minimum values at points 22, 23. Similarly, the cross-sectional area of transverse groove 19 is at its greatest value substantially midway between points 22, 23 and decreases to a minimum value at these points.

Grooved portion 16 is curved in section to receive the end portion 24 of electrical grounding conductor 25 and cylindrical bore 14 is adapted to receive end portion 26 of grounding rod 27 to join wire 25, rod 27 and head 10 in compressed relation as will be explained in greater detail hereafter.

In use end portion 24 of conductor 25 is bent into a loop and partially inserted into the grooved portion 16 of driving head 19 as shown in FIG. 3. The lower end portion 26 of ground rod section 27 is driven into cylindrical bore 14 by means of a hammer or other suitable device (not shown) until the rod 27 and conductor 25 are wedged into head It? as shown in FIG. 4. Conductor 25 is compressed between head ltl and ground rod 27 by the tapered grooves 17, 18 and is further afiixed in place by penetration of the end 28 of ground rod 27 into ground wire 25 at points 2% and 3b where the grooved portion 16 intersects the plane of bottom seat 15.

As the ground rod and driving point are driven into the ground in the usual fashion, carrying electrical conductor with it, the first section 33 of the driving rod having attached thereto a slip-fit coupling means 34 is inserted on the upper end of the grounding rod 27 and the assembly driven into the ground until the next driving rod section 32 can be added by joining with a suitable coupling 35, and so on until the driving point 10 reaches the desired depth below the ground surface 31 (see FIG. 1). In this fashion the driving rod is built up with a plurality of sections 32 and the first section 33. Ground rod section 27 and the first driving rod section 33 are joined to one another by axially removable slip-fit coupling means 34, whereas said first driving rod section 33 and the other driving rod sections above it are interconnected with one another by threaded or other suitable coupling means 35 or the like for axial removal from ground rod section 2'7 as a group when the driving point it) is located at its desired depth.

By utilizing a material for the driving point having high strength qualities, the wedging of the conductor into the driving point will tend to cause a slight elongation along the longer axis of the elliptical configuration. This action tends to shorten slightly the width of the driving point along its shorter axis. By proper design consistent with the strength and elastic limits of the materials used in the manufacture of the driving point a continuing force will always be applied along the longer axis of the driving point in use and thereby continue to apply a force to the conductor and ground rod combination to prevent loosening of the electrical contact between the ground rod and conductor. In other words it is a somewhat resilient connection.

Lateral spacer means 36, which may be fabricated of tape, metal or other suitable binding material, may be provided on an intermediate portion 317 of ground rod section 27 (see FIGS. 1 and 4) and is interconnected with the adjacent portion 38 of ground wire 25 to maintain the ground wire radially spaced from ground section 27 a sufiicient lateral distance to clear coupling means 34 so that the removable driving rod sections can be separated from the ground rod section 2'7 without difficulty at the end of the sinking operation.

I A second embodiment of driving point it is shown in FIGS. 6-8 inclusive which is generally similar to the first embodiment except that it has opposed peripheral grooved portions 39, 40 extending along opposite sides of central cylindrical bore 14 which have different diameters or lateral dimensions to accommodate electrical ground wires or conductors 41, 42 of different sizes. The respective end portions 43, 44 of the ground wires 41, 42 are bent at substantially right angles to their lengths as shown and then connected to the driving point 10 in the above described manner. If only the smaller diameter wire 41 is used, then it can be looped and interconnected with the driving point as in the first embodiment. This second embodiment makes it possible, where desired, to make one driving point and ground rod section do double duty when two different sized ground wires are to be grounded. In this connection it is to be recognized that the first embodiment can be used in a similar fashion to sink two ground wires of the same diameter where so desired.

It is thus seen that a novel combination driving point and compressor head, and also a combination grounding apparatus, is provided having unique and highly novel characteristics. Furthermore, the economies to be gained by having a removable driving rod provides a significant advance in the art.

While certain embodiments of the invention have been shown and described it is to be understood that changes and additions might be made by those skilled in the art without departing from the scope and spirit of the invention.

What is claimed is:

1. A driving point for electrical grounding apparatus comprising a tapered head having a generally elliptical cross-section and having a central bore extending axially into said head with a bottom seat portion, and a peripheral grooved portion of said head extending axially along opposed sides of said bore and having an intermediate bottom portion extending through said seat, the opposed upper ends of said grooved port-ion aligned with the major axis of said elliptical crosssection, the depth of said axially extending grooved portion gradually decreasing to minimum values at the junctions thereof with said inter mediate bottom grooved portion, said grooved portion adapted to receive the end portion of an electrical grounding conductor and said bore adapted to receive the end portion of a grounding rod to join said conduct-or, said rod and said head in compressed relation.

2. Electrical grounding apparatus comprising in combination a driving point, an electrical ground conductor, a ground rod section, and a driving rod, said driving point including a head having a bore extending into said head with a bottom seat portion, and a peripheral grooved portion of said head extending axially along opposed sides of said bore and having an intermediate bottom portion extending through said seat, the lower terminal end portion of said ground conductor disposed in said grooved portion, the lower end portion of the ground rod section being disposed in said bore against said ground conductor in compressing relation therewith along said opposed sides, and axially removable slip-fit coupling means releasably joining said driving rod and the ground rod section whereby said driving rod is removable from said ground rod section.

3. Electrical grounding apparatus comprising in combination a driving point, an electrical ground conductor, a ground rod section, and a driving rod, said driving point including a head having a bore extending axially into said head with a bottom seat portion, and a peripheral grooved portion of said head extending axially along opposed sides of said bore and having a curved intermediate bottom portion extending through said seat, the depth of said grooved portion gradually decreasing to minimum values at the intersections thereof with the plane of said seat, the lower terminal end portion of said ground conductor disposed in said grooved portion, the lower end portion of the ground rod section being disposed in said bore against said ground conductor in compressing relation therewith along said opposed sides, and axially removable slip-fit coupling means releasably joining said driving rod and the ground rod section whereby said driving rod is axially removable from said ground rod section.

4. Electrical grounding apparatus comprising in combination a driving point, an electrical ground conductor,

a ground rod section, and a multisection driving rod, said driving point including a head having a generally elliptical cross-section and having a central cylindrical bore extending axially into said head with a flat bottom seat portion, and a peripheral =grooved portion of said head extending axially along opposed sides of said bore and having a curved intermediate bottom portion extending through said seat, the depth of said grooved portion gradually decreasing. to minimum values at the intersections thereof with the plane of said seat, the lower terminal end portion of said ground conductor being looped and disposed in said grooved portion, the lower end portion of the ground rod section being disposed in said bore against said ground conductor in compressing relation therewith along said opposed sides and in crimping relation therewith at said intersections, axially removable slip-fit coupling means releasably joining said ground rod section and the adjacent driving rod section, the individual sections making up said driving rod section being interconnected with one another for axial removal as a group from said ground rod section.

5. Electrical grounding apparatus comprising in combination a driving point, an electrical ground conductor, a ground rod section, and a multisection driving rod, said driving point including a tapered head having a generally elliptical cross-section and having a central cylindrical bore extending axially into said head with a flat bottom seat portion, and a peripheral grooved portion of said head extending axially along opposed sides of said bore and having a curved intermediatebottom portion extending through said seat, the opposed upper ends of said grooved portion aligned with the major axis of said elliptical cross-section, the depth of said grooved portion gradually decreasing to minimum values at the intersections thereof with the plane of said seat, the lower terminal end portion of said ground conductor being looped and disposed in said grooved portion, the lower end portion of the ground rod section being disposed in said bore against said ground conductor in compressing relation therewith along said opposed sides and in crimping relation therewith at said intersections, lateral spacer means on an intermediate portion of said ground rod section interconnected with said ground conductor for maintaining said conductor radially spaced from said ground rod section, axially removable slip-fit coupling means releasably joining said ground rod section and the adjacent driving rod section, the other driving rod sections interconnected with one another for axial removal as a group from said ground rod section.

6. Electrical grounding apparatus comprising in combination a driving point, a pair of different diameter electrical ground conductors, a ground rod section, and a multisection driving rod, said driving point including a tapered head having a generally elliptical cross-section and having a central cylindrical bore extending axially into said head with a flat bottom seat portion, and a pair of peripheral grooved portions of said head having different diameters and extending axially along opposed sides of said bore and having intercommunicating bottom portions joining at said seat, the opposed upper ends of said grooved portions aligned with the major axis of said elliptical cross-section, the respective depths of said grooved portions gradually decreasing to minimum values at the intersections thereof with the plane of said seat, the lower terminal end portions of said ground conductors being bent at substantially right angles to their lengths and dis posed in the grooved portion corresponding to its size, the lower end portion of the ground rod section being disposed in said bore against said ground conductors in compressing relation therewith along said opposed sides and in crimping relation therewith at said intersections, axially removable slip-fit coupling means releasably joining said ground rod section and the adjacent driving rod section, the other driving rod sections interconnected with one another for axial removal as a group from said ground rod section.

7. Electrical grounding apparatus comprising in combination a driving point, a pair of dilierent diameter electrical ground conductors, a ground rod section, and a multisection driving rod, said driving point including a tapered head having a generally elliptical cross-section and having a central cylindrical bore extending axially into said head with a flat bottom seat portion, and a pair of peripheral grooved portions of said head having different diameters and extending axially along opposed sides of said bore and having intercommunicating bottom portions joining at said seat, the opposed upper ends of said grooved portions aligned with the major axis of said elliptical cross-section, the respective depths of said grooved portions gradually decreasing to minimum values at the intersections thereof with the plane of said seat, the lower terminal end portions of said ground conductors being bent at substantially right angles to their lengths and disposed in the grooved portion corresponding to its size, the lower end portion of the ground rod section being disposed in said bore against said ground conduc tors in compressing relation therewith along said opposed sides and in crimping relation therewith at said intersections, lateral spacer means on an intermediate portion of said ground rod section interconnected with said ground conductors for maintaining said conductors radially spaced from said ground rod section, axially removable slip-fit coupling means releasably joining said ground rod section and the adjacent driving rod section, the other driving rod sections interconnected with one another for axial removal as a group from said ground rod section.

8. A driving point for electrical grounding apparatus comprising a head formed to provide a socket extending inwardly from one end of the head and adapted for reception of one end of a grounding rod, a transverse groove at the bottom of said socket which is narrower than said socket and which extends transversely across the bottom of the socket and projects laterally on at least one side of the socket, and at least one axial groove extending lengthwise along one side of the socket to join with the end of said transverse groove, whereby at least one conductor may be driven into wedging engagement into said axial groove and said transverse groove by driving said rod into said socket.

9. A driving point for electrical grounding apparatus comprising a head formed to provide a socket extending inwardly from one end of the head and adapted for reception of one end of a grounding rod, a transverse groove at the bottom of said socket which is narrower than said socket and which extends transversely across the bottom of the socket and projects laterally on opposite sides of the socket, and axial grooves at opposite sides of said socket extending lengthwise thereof to join the projecting ends of said transverse groove, whereby at least one conductor may be driven into wedging engagement into at least one of said axial grooves and said transverse groove by driving said rod into said socket.

10. A driving point for electrical grounding apparatus as set forth in claim 9 wherein the cross-sectional areas of said axial grooves gradually decrease to minimum values at the points where said axial grooves join said transverse groove.

11. A driving point for electrical grounding apparatus as set forth in claim 9 wherein the cross-sectional area of said transverse groove is at its greatest value substantially midway between the points where said axial grooves join said transverse groove and decreases gradually to minimum values at said points.

12. A driving point for electrical grounding apparatus as set forth in claim 9 wherein said head is of generally elliptical cross-section and is adapted to form a resilient connection between said conductor and said grounding rod.

13. A driving point for electrical grounding apparatus as set forth in claim 9 wherein said axial grooves are of different dimensions whereby said head is adapted to accommodate simultaneously two conductors of different diameters.

References Cited in the file of this patent UNITED STATES PATENTS 1,154,099 Curry Sept. 21, 1915 1,679,677 Milne Aug. 7, 1928 2,107,835 Pierce Feb. 8, 1938 2,180,318 Deems Nov. 14, 1939 2,283,987 Hammar May 26, 1942 7 2,547,176 Salmons Apr. 3, 1951 FOREIGN PATENTS 10,265 Germany Nov. 25, 1879 70,546 Austria Nov. 25, 1915 

